Creatine is an endogenous nutrient produced naturally by the liver in most vertebrates. The uses of creatine are many, including use as a supplement to increase muscle mass and enhance muscle performance as well as in emerging applications in the treatment of neuromuscular disorders.
Typically, creatine is taken up into muscle cells by specific receptors and converted to phosphocreatine by creatine kinase. Muscle cells, including skeletal muscle and the heart muscle, function by utilizing cellular energy released from the conversion of adenosine triphosphate (ATP) to adenosine diphosphate (ADP). The amount of phosphocreatine in the muscle cell determines the amount of time it will take for the muscle to recover from activity and regenerate adenosine triphosphate (ATP). Phosphocreatine is a rapidly accessible source of phosphate required for regeneration of adenosine triphosphate (ATP) and sustained use of the muscle.
For example, energy used to expand and contract muscles is supplied from adenosine triphosphate (ATP). Adenosine triphosphate (ATP) is metabolized in the muscle by cleaving a phosphate radical to release energy needed to contract the muscle. Adenosine diphosphate (ADP) is formed as a byproduct of this metabolism. The most common sources of adenosine triphosphate (ATP) are from glycogen and creatine phosphate. Creatine phosphate is favored as a ready source of phosphate because it is able to resynthesize adenosine triphosphate (ATP) at a greater rate than is typically achieved utilizing glycogen. Therefore, increasing the amount of creatine in the muscle increases the muscle stores of phosphocreatine and has been proven to increase muscle performance and increase muscle mass.
However, creatine itself is poorly soluble in an aqueous solution. Further, creatine is not well absorbed from the gastrointestinal (GI) tract, which has been estimated to have a 1 to 14 percent absorption rate. Thus, current products require large amounts of creatine to be administered to be effective, typically 5 grams or more. Additionally, side effects such as bloating, gastrointestinal (GI) distress, diarrhea, and the like are encountered with these high dosages.
Therefore, it would be desirable to provide an improved approach for enhancing absorption of creatine.